We look at the division of 6650646 by 561 
The aim is to understand the frequency of 561 in 6650646.

On to step 1:
561 can be fit into 6 0 times, resulting in a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 6 leaves us with 6.
Fetch the next digit (6) from the dividend, attach it to 6 and continue: 66 / 561

Moving on to step 2:
The number 561 fits into 66 0 times, leaving a remainder of 66.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 66 after subtracting 0 from 66.
Grab the next digit (5) from the dividend, add it to 66, then carry on: 665 / 561

Advancing to step 3:
The number 561 fits into 665 1 times, leaving a remainder of 104.
Put 1 as the next digit of the answer. 
Result so far: 1.0
Subtracting 561 from 665 leaves us with 104.
Include the next digit (0) from the dividend after 104, then repeat: 1040 / 561

Moving on to step 4:
1040 divided by 561 is 1 with a remainder of 479.
Put 1 as the next digit of the answer. 
Result so far: 11.0
Subtract 561 from 1040 to get 479.
Append the next digit (6) from the dividend to 479 and continue with: 4796 / 561

Step 5:
4796 divided by 561 is 8 with a remainder of 308.
The next digit of our result is 8. 
Result so far: 118.0
If we subtract 4488 from 4796, we get 308.
Append the next digit (4) from the dividend to 308 and continue with: 3084 / 561

Let's proceed to step 6:
561 can be fit into 3084 5 times, resulting in a remainder of 279.
The number 5 becomes the next digit in our result. 
Result so far: 1185.0
Deduct 2805 from 3084 and we're left with 279.
Grab the next digit (6) from the dividend, add it to 279, then carry on: 2796 / 561

Moving on to step 7:
2796 divided by 561 is 4 with a remainder of 552.
The next digit of our result is 4. 
Result so far: 11854.0
Subtract 2244 from 2796 to get 552.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5520, and continue the process.

On to step 8:
If we divide 5520 by 561, we get 9 and a remainder of 471.
Write down 9 as next digit of the result. 
Result so far: 11854.9
Subtract 5049 from 5520 to get 471.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4710, and continue the process.

Moving on to step 9:
The number 561 fits into 4710 8 times, leaving a remainder of 222.
The number 8 becomes the next digit in our result. 
Result so far: 11854.98
The remainder is 222 after subtracting 4488 from 4710.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2220, and continue the process.

Advancing to step 10:
The number 561 fits into 2220 3 times, leaving a remainder of 537.
Use 3 as the next digit of our solution. 
Result so far: 11854.983
Subtract 1683 from 2220 to get 537.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5370, and continue the process.

On to step 11:
561 goes into 5370 9 times with a remainder of 321.
Record the quotient 9 as the next digit in the result. 
Result so far: 11854.9839
Subtracting 5049 from 5370 leaves us with 321.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3210, and continue the process.

Moving on to step 12:
561 goes into 3210 5 times with a remainder of 405.
Use 5 as the next digit of our solution. 
Result so far: 11854.98395
The remainder is 405 after subtracting 2805 from 3210.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4050, and continue the process.

On to step 13:
When dividing 4050 by 561, we get 7 with a remainder of 123.
Record the quotient 7 as the next digit in the result. 
Result so far: 11854.983957
Deduct 3927 from 4050 and we're left with 123.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1230, and continue the process.

Step 14:
If we divide 1230 by 561, we get 2 and a remainder of 108.
The number 2 becomes the next digit in our result. 
Result so far: 11854.9839572
The remainder is 108 after subtracting 1122 from 1230.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1080, and continue the process.

Step 15:
1080 divided by 561 is 1 with a remainder of 519.
Use 1 as the next digit of our solution. 
Result so far: 11854.98395721
If we subtract 561 from 1080, we get 519.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5190, and continue the process.

In conclusion, the division gives 11854.98395721 with a balance of 5.19e-07.